Known roof boxes are closed or respectively sealable containers for storing luggage that enable the additional transportation of luggage, such as ski equipment, with a motor vehicle outside of conventional storage spaces such as the luggage compartment. They are mounted on the roof of the motor vehicle, generally on a roof rack or on roof rails provided by the manufacturer for this purpose. A roof box increases the fuel consumption of a motor vehicle since they increase the weight and air resistance of the motor vehicle. In addition, the vehicle noise increases, and the achievable or permissible maximum speed of the vehicle is reduced. If the additional luggage compartment of the roof box is not required, the roof box must be removed and stored somewhere else. A significant amount of space is required to store the roof box which is especially disadvantageous when no suitable garage or storage area is available.
A motor vehicle roof body part of a motor vehicle is known from DE 60 2005 002 301 T2 and is designed as a container that delimits a storage space, wherein this container is equipped with a flap accessible from the outside of the motor vehicle. This container is therefore designed integrated into the roof of the motor vehicle and therefore does not have to be mounted or removed. This also reduces fuel consumption and vehicle noise. A disadvantage is, however, that the container only provides an extremely limited storage space since the height of the container is restricted to the thickness of the motor vehicle roof.